Speed control apparatus for a fluid-type engine



SPEED coNTRoL APPARATUS Fon A FLUID-TYPE ENGINE I Filed July 27,' 1962 C. H. BAKER April 27, 1965 2 Sheets-Sheet 1 NVENTOR.

CHARLES H. BAKER BY c\ www N A ATTRNEY .April 27, 1955 c. H. BAKER 3,180,081

SPEED CONTROL APPARATUS FOR A FLUID-TYPE ENGINE Filed July 27, 1962 Y l *2 Sheets-Sheet 2 84-" am@ 7- s6 FIG. 2

I INVENTOR.

CHARLES H. BAKER MTGRNEY United States Patent O 3,180,081 SPEED CDNTRQL APPARATUS FR A FLUID-TYPE ENGlNE Charles H. Baker, Cleveland, Ohio, assigner to Cleveland Pneumatic industries, Inc., Cleveland, (lhio, a corporation of Chio Filed July 27, 1962, Ser. No. 212,831 9 Claims. (Cl. Gil-24) Broadly, this invention relates to a thermodynamic engine in which a working fluid traverses a thermodynamic cycle to produce power and more particularly pertains to a novel means for controlling the speed of the engine.

In an engine of the type disclosed herein, a working uid compressed and heated is expanded against a working surface within an expansion chamber of a piston and cylinder arrangement to produce mechanical power. The working uid, in an linitial condition in a compression chamber, is compressed then heated and subsequently directed to an expansion chamber Where it expands against the working surface. After expansion and at a reduced temperature and pressure, the working iluid is directed to a cooling heat exchanger unit where it is cooled to its initial (before compression) condition. In a fluid-type engine, the above set forth thermodynamic cycle is traversed by a suitable working fluid having desirable volumetric expansion characteristics and advantageous thermal properties. It is desirable further to provide suitable means for controlling the speed at which the iiuid-type engine operates and to ei`ectively provide such control utilizing a device which can be readily actuated to obtain the desired results.

Therefore, it is the principal object of this invention to provide apparatus cooperable with a fluid-type engine and system arrangement in which a working fluid traverses a thermodynamic cycle wherein such apparatus is operable to control the speed of the engine.

It is another object of this invention to provide apparatus cooperable with a fluid-type engine and system arrangement in which a working iiuid traverses a thermodynamic cycle wherein the apparatus is operable to control the speed of the engine and is disposed intermediate the expansion chamber and the cooling heat exchanger in the system.

It is still another object of this invention to provide apparatus cooperable with a fluid-type engine and system arrangement in which a working uid traverses a thermodynamic cycle wherein the apparatus comprises a valve and conduit arrangement operable to convey the working liuid from the expansion chamber directly to the compression chamber of the engine by-passing the cooling heat exchanger and thereby effective to control the speed of the engine.

A further object of this invention is to provide apparatus cooperable with a duid-type engine and system arrangement in which a working fluid traverses a thermodynamic cycle wherein the apparatus controls the speed of the engine and is simple in design and construction and can be economically produced.

These and other objects and important features of the invention will be apparent from a study of the specification following taken within the drawing, which together show, illustrate, describe and disclose certain preferred embodiments and modifications of the invention and what is now considered to be the best mode of practicing the principles thereof. Other embodiments or modifications may be suggested to those having the benet of the teaching herein, and all such embodiments or modifications are intended to be reserved as they fall within the spirit and scope of the subjoined claims.

3,l80,8l Fatented Api'. 2?',1965

ice

In the drawing:

FIGURE 1 is a schematic illustration partially in crosssection of a systemV having a fluid-type engine employing a thermodynamic cycle showing apparatus incorporated therewith for controlling the speed of the engine.

FIGURE 2 is an enlarged crosssectional view of the speed control apparatus illustrating the valve and conduit arrangement and the component parts thereof communicating the working uid, after expansion, from the expansion chamber with the cooling heat exchanger.

FIGURE 3 is an enlarged crosssectional view of the valve and conduit arrangement of FIGURE 2 illustrating therein the by-pass valve in a partially opened position operable in this position to convey a portion of the working fluid from the expansion chamber directly to the compression chamber by-passing the cooling heat exchanger. w

Attention is now directed to FIGURE 1 of the drawing, in which a system 10 is illustrated in partial schematic'Y form wherein the system 10 is, in effect, closed, and comprises, as a part thereof, a fluid-type engine 12 having a block 14 in which a cylinder 16 is bored and a piston 18 is reciprocably mounted. The piston 18 is secured to a connecting rod 20 and a crankshaft 22 arrangement disposed in a crankcase chamber 24 formed by a housing 26. The piston 18 comprises an enlarged base portion 28 and an extended reduced portion 30 forming a shoulder therebetween. The shoulder 32 has a workingrsurface 34, thereon, forming one wall of a compression chamber 36 and the extended reduced portion 30 has a working surface 38 thereon forming one wall of the expansion chamber 40. The structural details of the piston 18 and the arrangement thereof with the engine block 14 are more specifically described, disclosed, shown, illustrated and claimed in the U.S. application Serial Number 213,401, led July 30, 19,62, in the name of the instant inventor and assigned to the Yassignee of the present invention.

The compression chamber 36 has an inlet port 42 and an outlet port 44 circumferentially spaced and suitably arranged about the engine block 14 with the ports 42 and 44 each being communicable with the compression chamber 36. The outlet port 44 has a check valve 46 communicable therewith wherein working Vfluid F from the compression chamber is directed through 'the outlet Yport 44 and the check valve 46 into a conduit 48 and tion of the valve 52 and the accumulator arrangement 54 `is more specifically described, disclosed, illustrated, shown and claimed in the U.S. application Serial Number A 222,729, filed September 10, 1962, in the name of Stanley A. Weiland and assigned to the assignee of the present invention. A conduit 56 connects the power heat exchanger 50 to an inlet valve 58 disposed adjacent one end portion ofthe engine block 14 in communication with the expansion chamber 40. An outlet valve 60 is also disposed at one end portion of the engine block adjacent the inlet Valve 58 to provide communication of the working iiuid F in the expansion chamber 40 with a conduit 62. The conduit 62 directs the working fluid F from the expansion chamber 64 therefrom through a conduit 65 into an inlet valve 68 connected to the inlet port 42 communicable with the compression chamber 36. The bypass valve 70 is disposed in luid communication with a conduit '74 connected to conduit 66 in the system and the specifics thereof will be describedV in detail hereinafter.

An oil separator 72 is connected to the conduit 62 intermediate the by-pass valve 70-and the cooling heat exchanger 64, wherein lubricating oil from the working fluid with which it passes through the system during the operating cycle thereof is separated. The oil separator 72 is connected to a filter 73 which is connected to the engine crankcase housing 26, by suitable conduits. The lubricating oil enters into the system by conventional pumping means which directs the oilfrom the crankcase into the piston and through suitable passageways (not shown). Lubricating oil as directed, is thereby disposed onto the cylinder walls and into the compression chamber becoming commingled with the working uid. The specific details of the oil separator 72 and the filter 73 in combination with the system 10` is more fully described, disclosed, shown, illustrated and claimed in the U.S. application Serial Number 191,075 tiled April 30, 1962, now Patent No. 3,138,918 in the name of the instant inventor and assigned to the assigneeV of the present invention.

In order to compensate for certain conditions or factors, such as variations in the temperature of the working uid F resulting from the effect created thereon by the power heat exchanger 50 and the eiective cooling of the working uid F resulting from the heat exchanger 64, as well as providing for the substitution of different types of working fluid which may be employed in the system 10 to operate the fluid-type engine 12, there is provided apparatus which ymay take the form of a compensator or engine multiplier device 75. The specic details of the compensator or engine multiplierware more fully described, disclosed, shown, illustrated and claimed in the U.S. application` Serial Number 202,285 filed lune 13, 1962, in the name of the instant inventor and assigned to the assignee of the present invention.

In order to control the speed of the fluid-type engine 12, there is provided the by-pass valve 70 and conduit arrangement disposed in the system as above set forth wherein the by-pass valve 70 (FIGURE 2) comprises a housing k74S in which is disposed an annular plate 78 pivotally mounted on a shaft 80 extending through the housing l76. Formed integral with the plate 78 is a shoulder portion 82 having a radius of curvature thereon equal to the radius of curvature of the plate 78. A porting arrangement is formed in the housing 76 wherein an inlet port S4 is'in communication with the conduit 62 extending from the expansion chamber 40 of the fluid-'type engine 12 and an outlet port 86 in communication with the conduit 62 extending from the by-pass valve 70 and connected to the oil separator 72. An outlet port S8 is provided in the valve housing 76 in communication with the inlet port 84 and the conduit 74 responsive to the pivotal movement of the shoulder 82. As disclosed in FIGURE 2, iluid entering the inlet port will proceed therethrough to outlet port 86 and into conduit 62 for communication with the oil separator 72 and cooling heat exchanger 64. At such time when it is desirable to control the speed of the engine, pivotal movement of the plate 78-and accordingly the shoulder S2 in a counter-clockwise direction will open port 88 ,inV

communication with conduit 74 and simultaneously reduce communication by an equal amount between the outlet port 86 and conduit 62. The control means (not shown) for imparting pivotal movement in the plate can be manually or automatically operated-.and accordingly depending upon the desired speed of the huid-type engine, rotation of the plate 78 and shoulder 82 will open or close in varying degrees the fluid ports in communication with conduits 62 and 74.

In order to more clearly illustrate the inventive concept described, disclosed and shown herein by which Vthe by-pass valve 70 and the conduit arrangement 74 is utilized to control the speed of the uid-type engine a typical operating cycle of the engine is setforth herein. Accordingly, the cycle will be described only to the extent necessary for a complete understanding of the present invention with values for the temperatures and Y engine operation.

4. pressures experienced by the working tluid F being merely exemplary and constituting representative amounts for illustrative purposes only.

In operation, a unit mass of working fluid F such as carbon dioxide at a temperature of approximately 70 F., is compressed in the compression chamber 36 to a pressure of approximately 6,000 p.s.i. and a temperature of approximately 3007 F. At this temperature and pressure the carbon dioxide isV directed through the outlet port 44, the outlet valve 46 and into the conduit 48. The valve 46 can be pressure responsive or actuated by suitable means (not shown) and synchronized in relationship to the cooperating elements of the cycle during The compressed working huid in the conduit 4S is directed through the valve 52 of the accumulator arrangement 54 and into the power heat exchanger 50 in which heat from any suitable source is applied to the working luid F to substantially raise its temperature to approximately 500 F. while the pressure remains substantially constant. At this temperature and pressure, the carbon dioxide enters the inlet valve S8 through conduit 56 and upon synchronized opening of the inlet valve by suitable means (not shown) the working fluid F is directed to the expansion chamber 40. When the working fluid enters the expansion chamber 40, the increased volume therein provided causes the carbon dioxide to expand so that a given mass of working uid F has a greater volume when it enters the expansion chamber 40 than it has as it is pumped out of the compression chamber 36. This expansion reduces the pressure and in turn reduces the temperature adiabatically. The piston 18 at this stage of the operation, is in the top dead-center position and upon expansion of the carbon dioxide, is moved downwardly against the connecting rod 20 and the crankshaft 22 arrangement imparting rotative movement to the crankshaft. Upon continued rotation of the crankshaft 22, through the rotation of a iiywheel (not shown) attached thereto, the piston 18 is directed upwardly and the outlet valve 60 is opened allowing the escape of the expanded carbon dioxide at a reduced temperature and pressure 0f approximately 200 VF. and 800 p.s.i. respectively, from the expansion chamber 40 into the conduit 62 through the by-pass valve 70 arrangement, as shown in FIGURE 2 of the drawing, and into the cooling heat exchanger 64. The by-pass valve, in an opened position, permits the ilow of the expanded worldng fluid F to continue through the conduit 62 and into the cooling heat exchanger 64. Upon leaving the cooling heat exchanger 64, the working fluid F is reduced to a temperature of approximately 70 F. and a pressure of 800 p.s.i and enters the inlet valve 68 through the conduit 66. Simultaneously with the expansion stroke, the inlet valve 68 opens to permit the carbon dioxide at the low temperature and pressure values to enter the compression chamber 36 whereupon the cycle is` then repeated.

If it is desired to reduce the speed and accordingly Vthe output of the fluid-type engine, manipulation of the plate 7S of the valve 70 in a counter-clockwise direction, will cause the shoulder 82 to provide fluid communication of the inlet port 84 through the outlet port 88 with the conduit 74. Such movement of the plate 73 will simultaneously reduce the outlet opening 86 and decreaseV the amount of working fluid flow from the expansion chamber 40 into the cooling heat exchanger 64. As the working fluid at the reduced temperature of approximately 200 F. and S00 p.s.i. enters the conduit 74 through the port 88 of the by-pass valve 70, the working `iluid at the respective temperatures and pressures will enter the conduit 66, the inlet valve 68, inlet port 42 and the compression chamber 3'6 of the fluid-type engine 12. A unit mass of carbon dioxide at the respective temperature and pressure, provided after expansion in the expansion chamber will occupy a larger volume and accordingly be less dense in the available volume o the compression chamd ber Therefore, upon completion of the compression stroke of the piston if, a lower unit pressure in the carbon dioxide will be obtained. Upon opening of the outlet valve 46 the working fluid Fvdirected therethrough into the conduit d?. and into the power heat exchanger Sil at a relatively high temperature and low pressure and consequently will be unable to receive a quantity of heat by comparison with the working fluid directed through the cooling heat exchanger ed. The differential in the temperatures and pressures of the fluid from the expansion chamber to the compression chamber will be substantiall smaller by the above recited comparison. Upon entering the expansion chamber, the fluid being at a pressure substantially less than the available pressure which could have been obtained through the entire passage of the iluid in the cooling heat exchanger 64, the working uid will be incapable of providing the volumetric expansion equal to the expansion of the liuid experiencing the cooling stage of the cycle. Therefore, this reduction in the volumetric expansion will result in a corresponding reduction in the force imparted to the piston head 3S and thereby substantially reduce the speed of the fluid-type engine l2.

it can be readily seen that desired mixtures of fluid directed from the expansion chamber 4t? into the cooling heat exchanger ed and into the compression chamber 36 can be obtained in the range from maximum speed where the by-pass valve is closed and the shoulder 82 is completely blocking the liuid communication between the outlet port 8S and the conduit '74- to a minimum engine speed wherein the by-pass valve provides complete iluid communication of the conduit 62 leading from the eX- pansion chamber il with conduit 74.

The duid-type engine i12,V as shown, discloses a single piston l@ and cylinder lo arrangement, however, it is within the scope of the invention described herein to provide a multiplicity of such piston and cylinder arrangements within the engine block 14 and correspondingly provide a by-pass valve and conduit arrangement in communication with a system comprising a multiple piston and cylinder embodiment.

While the invention has been described, disclosed, illustrated, and shown in terms of certain embodiments or modifications which is assumed in practice, the scope of the invention should not be deemed to be limited to the precise embodiments and modifications herein described, disclosed, illustrated or shown, since other embodiments and modifications are intended to be reserved where they fall within the scope of the claims herein appended.

I claim as my invention:

l. Speed control apparatus for a uid-type engine in which a working uid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling, said apparatus comprising:

conveying means for enabling at least a portion of such working fluid to traverse the thermodynamic cycle with such portion of the working iiuid bypassing the cooling stage and passing from said expansion stage directly to said compression stage, and

control means operatively associated with said conveying means effective to control the flow of such portion of the working .tluid therethrough.

2. Speed control apparatus for a fluid-type engine in which a working fluid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling, according to claim l, wherein said control means is in uid communication with said conveying means and is selectively operable to direct such portion of said working uid from said expansion stage through said conveying means directly to said compression stage of said cycle.

3. Speed control apparatus for a huid-type engine in which a working uid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling, according to claim 1, wherein said conveyarancel ing means for such portion of working fluid comprises conduit means in which said working fluid flows.

4. Speed control apparatus for a `duid-type engine in which a working duid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling, according to claim 3, wherein said conduit means is connectedwith said fluid engine in tluid communication with said expansion stage and said cornpression stage of said thermodynamic cycle.

5. Apparatus for controlling the speed of a duid-type engine Vin which a working fluid Jtraverses a thermodynamic cycle comprising the sequential stages of compression, heating, expansion and cooling, said apparatus comprising:

conduit means connected to said huid-type engine for conveying directly, said working tiuid from said eX- pansion stage to said compression stage While bypassing the cooling stage of the thermodynamic cycle, and

control means disposed in communication with said conduit means,l said control means being operable to open and close fluid communication in said conduit means from said expansion stage Vwith said compression stage of said cycle and effective upon opening to control the speed of said lluid-type engine.

6. Apparatus for controlling the speed of a duid-type engine in which a working uid traverses a thermodynamic cycle comprising the sequential stages of compression, heating, expansion and cooling, according to claim 5, wherein said control means comprises a valve device.

7. In combination with a fluid-type engine and system arrangement in which a working tluid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling and having a piston and cylinder arrangement defining an expansion and compression chamber, apparatus for controlling the speed of said engine comprising:

means for providing communication of said working fluid from said expansion chamber directly to said compression chamber of said engine with said working iluid bypassing the cooling stage of the thermodynamic cycle, and

control means operatively associated with said means for varying said communication of said working liuid effective to control the speed of said engine. Y 8. ln combination with a duid-type engine and system arrangement in which a working uid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling and having a piston and cylinder arrangement delining an expansion and compression chamber, apparatus for controlling the speed of said engine according to claim 7, wherein said means for providing communication of said working fluid from said eX- pansion chamber directly with said compression chamber and said control means comprise conduit means and a valve arrangement.

9. in combination with a fluid-type engine and system arrangement in which a working uid traverses a thermodynamic cycle comprising the stages of compression, heating, expansion and cooling and having a piston and cylinder arrangement defining an expansion and compression chamber, apparatus for controlling the speed of said engine according to claim 8, wherein said valve arrangement is disposed in fluid communication with said conduit means and being selectively operable to direct huid from said expansion chamber through the conduit means and into said compression chamber while bypassing said cooling stage ot said thermodynamic cycle and thus electively control the yspeed of said engine. y Y

References Cited by the Examiner UNITED STATES PATENTS 2,643,508 6/53 Clay et al. 60--24 JULIUS E. WEST, Primary Examiner. ROBERT R. BUNEVICl-I, Examiner. 

1. SPEED CONTROL APPARATUS FOR A FLUID-TYPE ENGINE IN WHICH A WORKING FLUID TRASVERSE A THERMODYNAMIC CYCLE COMPRISING THE STAGES OF COMPRESSION, HEATING, EXPANSION AND COOLING, SAID APPARATUS COMPRISING: CONVEYING MEANS TO ENABLING AT LEAST A PORTION OF SUCH WORKING FLUID TO TRAVERSE THE THERMODYNAMIC CYCLE WITH SUCH PORTION OF THE WORKING FLUID BYPASSING THE COOLING STAGE AND PASSING FROM SAID EXPANSION STAGE DIRECTLY TO SAID COMPRESSION STAGE, AND CONTROL MEANS OPERATIVELY ASSOCAITED WITH SAID CONVEYING MEANS EFFECTIVE TO CONTROL THE FLOW OF SUCH PORTION OF THE WORKING FLUID THERETHROUGH. 